ARM: dts: BCM53573: Disable second Ethernet on Luxul devices

XAP-810 and XAP-1440 both have a single Ethernet port and BCM54210E PHY.
Their second Ethernet interface is not connected to anything.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20230724101159.5289-1-zajec5@gmail.com


Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>